package 网络编程;


import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.ServerSocket;

public class UdpEchoServer {
    private DatagramSocket socket=null;
    public UdpEchoServer(int port) throws IOException {
        socket=new DatagramSocket(port);
    }
    public void start() throws IOException {
        while(true){
            System.out.println("服务器启动成功！");
            DatagramPacket requestPacket=new DatagramPacket(new byte[1024],1024);
            socket.receive(requestPacket);
            String request=new String(requestPacket.getData(),0,requestPacket.getLength());
            String response=process(request);
            DatagramPacket responsePacket=new DatagramPacket(response.getBytes(),response.getBytes().length,requestPacket.getSocketAddress());
            socket.send(requestPacket);
            System.out.printf("[req:%s,resp:%s] req:%s resp:%s\n",requestPacket.getAddress().toString(),requestPacket.getPort(),request,response);
        }
    }
    public String process(String request){
        return request;
    }

    public static void main(String[] args) throws IOException {
        UdpEchoServer server=new UdpEchoServer(9090);
        server.start();
    }
}
